Method and apparatus for destructive distillation of solid hydrocarbonaceous materials including reactions between gases and unsized solids and the physical separation thereof



Oct. 28, 1969 METHOD AND APPARATUS FOR DESTRUCTIVE DIS'IILLATION OFSOLID HYDROCARBONACEOUS MATERIALS INCLUDING REACTIONS BETWEEN GASES ANDUNSIZED SOLIDS AND THE Filed Dec. 10, 1965 M. G. HUNTINGTON PHYSICALSEPARATION THEREOF 5 Sheets-Sheet 1 TAIL GAS To PREHEAT RAW MATERIAL HG]50s I SOUD HYDROCARBONACEOUS SOLTDT HEATTNG 522 SUPPORTED RAW MATERIALSCATALYST (CRUSHED) 5 1 2 g o [J 506 5 FINE GAS -soun q T g 502 Loc KsEPARAToR, 508 9 METERED VOLATILE 4 MATTER ENTRAIN SECONDARY w 0CATALYST 500 H A w z g AAREETHEEKETEDEH Ll-l 2 5'8 SECONDARY o CATALYSTL------ T- g 2/6! a g S, 50 METERED a E REACTOR PREHEATED H2 3 SECONDARYC0] El CATALYST Z 2 A, 2 z 5 3 508 METERED& PREHEATED H2 3 SECONDARY oCATALYST 50s sm S METERED a PREHEATED H2 520 LOCK 512 INVENTOR T MORGANe. HUNTINGTON SEPARATOR cATALYsT o T A A, W, HEATING souo E] BY 2A,, MAI/ SHALE CALCINE y ATTORNEYS M; G. HUNT|NGTON Oct. 28, 1969 3,475,317METHOD AND APPARATUS FOR DESTRUCTIVE DISTILLATION OF SOLIDHYDROCARBONACEOUS MATERIALS INCLUDING REACTIONS BETWEEN GASES ANDUNSIZED SOLIDS AND THE PHYSICAL SEPARATION THEREOF 5 Sheets-Sheet 3Filed Dec. 10, 1965 E T e )1 ET WT W TS PE V .L U D EL V F. E E R 0 mm vmm no E H MG D T E m m E m W H m m A u M m D H W S 5 T 7 AE M v E 9 l! LAWIL F. 1 M N |Dn DU D .I L m mn A PT RAM A E EE D DI. .I D DD E E N nDn M Y A E M N US A F MG P K/ 8 FIGS Oct. 28. 1969 M. G. HUNTINGTON3,475,317

METHOD AND APPARATUS FOR DESTRUCTIVE DISTILLATION OF SOLIDHYDROCARBONACEOUS MATERIALS INCLUDING REACTIONS BETWEEN GASES ANDUNSIZED SOLIDS AND THE PHYSICAL SEPARATION THEREOF Filed Dec. 10, 1965 5Sheets-Sheet 4 FIGS 5 2: l 5 :3 a PIEIEI TID TERED VENT Q HYDROGEN] l ME425 m 4w PURGE GAS 5 J METERED INLET 420 '7' 419 2 423 Q 421 g GASDIKFIHSI Z METERED PURGE GAS 2 PURGE GAS 7 OUTLET E METERED INLET I 435l- 2 7 429 46L 4 \JITI T0 SCEENS FOR SOLID CATALYST RECOVERY AND FORHEATING MEDIUM SEPARATION WHEN HOT SOURCE IS OTHER THAN SUPERHEATEI)CHAR 0R CALCINE METERED GAS INLET CDALESCING TEETEFI COLUMN I?SEPARATION 5 Sheets-Sheet 5 GYRATDRY FEEDER SHELF EMPTY SPACE HUNTINGTONGAS SOLID CONTACT ZONE PHYSICAL SEPARATION THEREOF u i L II n BETWEENGASES AND UNSIZED SOLIDS AND THE HYDROCARBONACEOUS MATERIALS INCLUDINGREACTIONS METHOD AND APPARATUS FOR DESTRUCTIVE DISTILLATION OF SOLIDOct. 28, 1969 Filed Dec. 10. 1965 DOWNCOMER METERED GAS-VAPOR OUTLETSUPERFICIAL VERTICAL GAS VELOCITY I/2FT/Sec.

ETERED VAPOR OUTLET DOWNCOMER GAS GYRATORY FEEDER SHELF EMPTY SPACE ZONEGAS- SOLID CONTACT EMPTY SPACE METERED GAS INLET Patented Oct. 28, 19693,475,317 METHOD AND APPARATUS FOR DESTRUCTIVE DISTILLATION F SOLIDHYDROCARBONA- CEOUS MATERIALS INCLUDING REACTIONS BETWEEN GASES ANDUNSIZED SOLIDS AND THE PHYSICAL SEPARATION THEREOF Morgan G. Huntington,P.O. Box 81, Galesville, Md. 20765 Filed Dec. 10, 1965, Ser. No. 513,017Int. Cl. Cltlb 53/06; Cg 23/06, 37/06 US. Cl. 208-10 17 Claims ABSTRACTOF THE DISCLOSURE A method and apparatus for the destructivedistillation of hydrocarbonaceous materials is disclosed. The apparatusand process include a means for feeding at least a solid supportedcatalyst and a crushed hydrocarbonaceous raw material through a lock andto a vertical reactor capable of withstanding temperatures of up to 2000F. and pressures to 30 atmospheres. The reactor contains a plurality ofadjacent vertically positioned distillation zones, gaseous intakeand'oiftake means for each zone, means for providing a gaseous diffusionbarrier between zones, and a combination A.C. agglomerator and wideninggaseous paths in each zone in front of the oiftake means. The reactor isfurther provided with a second lock means to allow for the removal ofthe solid'material which is subsequently passed to a system whichseparates eflluent solids. Preheated hydrogen is fed into each zone,entrains the destructively distilled and stabilized product and ispassed through a plurality of dephlegmators and catalyst beds. Thecatalyst in the reactor may be rejuvenated and recycled to the originalfeed means and a solid heating medium may be utilized in the reactor andcontinuously recycled.

This invention relates to a method'of contacting gases and brokensolids,part or all of which may be finely pulverulent and particularly relatesto the separation of entrained solids by settlement against a risingstream of gases. This invention also relates to. the improvement ofsettlementby increasing the mass of individual teetering particlesthrough impinging the finer dispersoids thereupon by electrical means.

This invention also relates to method and apparatus for the step-wiseexchanging ofheat between two or more mixed classes of formed or brokensolids, part of which may be finely pulverulent, wherein a gasconsisting mainly of hydrogen performs the essential function ofintermediate heat transfer agent.

This invention further relates to the extraction of vapors and gasesdestructively distilled from pulverulent gangue by entrainment withinand displacement by a wash gas which consists chiefly of hydrogen.

It is a particular relation of this invention that, to obtain maximumultimate yield of the more valuable hydrocarbons, the primary vaporsdestructively distilled from hydrocarbonaceous substances are broughtinto con-tact with a hydrogenation and stabilizing catalyst at theearliest possible instant. It is a further feature of this inventionthat such early vapor phase catalysis is achieved through the means ofadmixing physically separable and recoverable catalyst pellets with thehydrocarbonaceous material undergoing destructive distillation.

This invention also relates to the sequential contacting of descendingcolumns of solids by different gases whereby, for example, a combustiblegas may be exchanged for a noncombustible gas and whereby the mixing ofthe exchanging atmospheres can be controllably minimized.

The distillation apparatus of the subject invention is essentially asolid-gas-solid contactor of columnar configuration. Two or morephysically separable solids may be charged at the top of the columntreated in a hydrogen atmosphere and removed at the bottom undernon-explosive conditions, after exchanging hydrogen for flue gas, forexample. During the controlled movement of the solids from top tobottom, the solids are alternately held in position for optimumsolid-gas-solid contact and alter nately dropped through streams of gasto achieve optimum gas-solid contact and entrainment of evolving vapors.Also, during passage through the columnar system, two or more differenttypes of gases may contact the moving solids while mixing of thedifferent atmospheres is minimized.

The column may be operated through a wide range of pressures fromsub-atmospheric to a high positive pressure.

The addition of heat to, or the removal of heat from, a mass of unsized,finely divided broken solids is a difficult and time-consumingoperation, especially in cases where a substantial portion of the solidmaterial is finer than 50 microns and which will therefore pass a 300mesh sieve. Moreover, the mechanical problem of heating and/- or coolingis further complicated when the process also requires that the finelydivided solids be intimately contacted by a large volume of gas andfurther, that the gas be continuously introduced and removed from thesystem without substantial entrainment of the solid material. The rapidheat transfer and/ or chemical reaction between two or more types ofunsized solids, parts of which may be finely pulverulent, andparticularly, to perform this heat exchange within a moving gas stream,presents a number of complex mechanical problems which have notheretofore been satisfactorily solved to the extent of permittingcommercialization of such a process.

It is therefore, an objective of this invention to effect heat transferand/or chemical reactions between two or more classes of unsized solidsand to facilitate the admixing of large volumes of gas intermittentlytherewith, without serious entrainment of the finely divided parts ofthe solid phase as the gas stream and the solid materials are separatelyand continuously introduced and removed from the system.

Further, when the reacting gas of the subject invention is combustible,as is hydrogen for example, the mechanical difiiculties of charging anddischarging solids are rendered even more complex by the hazard ofexplosion unless the mixing of atmospheric oxygen can be absolutelyprevented. The avoidance of an explosive mixture of gases is especiallydifficult during the charging and discharging of hot solid materials,particularly when the system operates at a pressure other thanatmospheric.

Therefore, it is also an important object of this invention to providethe means of insuring against the explosive mixing of gases, Whilepermitting the 'free charging and discharging of fluids and solids whileoperating a reacting vessel within which gas-solid and solid-solid heatexchanges are performed and wherein gas-solid and gasvapor chemicalreactions may occur.

When destructively distilling hydrocarbonaceous solids, it has beennoted that strongly exothermic reactions occur between 700 F. and 900 R,which encompasses the temperature range within which all condensableliquids are distilled. The evolution of 60 to B.t.u. per pound of coal,for example, is attributed to the formation of the typical coke polymerand to other intermolecular reactions which produce high boilingcompounds. In order to maximize the yield of liquid distillate from oilshale and from other hydrocarbonaceous material, it has been foundadvantageous to entrain the volatiles in hydrogen and at the earliestpossible instant, to bring the pregnant stream into contact with astabilizing catalytic surface.

It is therefore a particular object of this invention to catalystpellets with the charged material. Ideally, in the case of oil shale,finely powdered shale would thinly surround relatively large pellets ofa physically separable catalyst. The catalyst pellets would preferablyhave a substantially greater heat capacity per unit area as compared tothe crushed shale particles and, therefore, the catalyst surface wouldrise in temperature more slowly than the shale particles. As thehydrogen atmosphere rises in temperature to effect the destructivedistillation of the oil shale, ideally, all of the initial vapors wouldinstantly contact the hydrogen-adsorbed catalytic surfaces of theadmixed pellets, whereupon all olefinic double bonds would be promptlysaturated and all oxygen would be removed from organic combination. Asthe result of such early catalytic stabilizing contact. very littleliquid phase would result from vapor phase polymerization to carbonizewithin the shale gangue particles. Also ideally, the flowing hydrogenwould rapidly carry the catalytically stabilized vapors away from thehot calcine for immediately quenching to a temperature somewhat belowthe maximum temperature of destructive distillation.

Certain hydrocarbonaceous solids, such as bituminous coals which have anoxygen content below 12%, actually melt and, if left undisturbed, willtend to cake during destructive distillation. However, if the normallycaking coal is mixed with a physically separable hydrogenating catalystin a hydrogen atmosphere the formation of the secondary coke polymer islargely avoided and if the entire mixture is kept in motion so that thejuxtaposition of particles is continuously changing, practically nocaking will result.

It is, therefore, an additional object of this invention to produce anessentially non-agglomerated char by the catalytic hydrodistillation ofbituminous coals which would otherwise be classified as caking.

It must be pointed out that there are three time-dependent limitingfactors which govern the throughput rate capacity of the system whendestructively distilling any hydrocarbonaceous solid. The first limitingfactor is the rate at which gas entrained vapors can be separated fromfinely divided solid matter; the second rate limiting factor is the timerequired for heat to be transferred from the solid heating medium to theraw material in order to raise the temperature of the latter to effectdestructive distillation; the third time-dependent factor is the rate atwhich the raw material is impoverished of its volatile matter afterhaving reached the temperature of destructive distillation.

In summary, the principal objects of this invention are:

(a) To limit superficial gas velocities within the conicocylindricalgas-solid separation zone to, say, one-half foot per second at thesection of its least horizontal area, and to cause the teetering solidsto agrninate and grow in size by electrical means.

(b) To provide optimum solid-gas-solid contact in hydrogen so that theraw material can be brought to the desired temperature quickly bytransfer of heat from the admixed heat source.

(c) To provide adequate residence time of the raw material to effect thepractically complete evolution of volatiles while effecting step-wiseevolution of volatile matter from the calcining mass by entrainment in awash gas.

(d) To mix with the solid hydrocarbonaceous materials duringdistillation a recoverable catalyst having a greater heat capacity perunit surface area than the solid hydrocarbonaceous materials and toscreen out and recycle the catalyst after destructive distillation iscompleted.

(e) To minimize carbonization upon a secondary catalyst by removing highboiling compounds, mist and small solids and to adjust temperature ofthe gas-entrained vapors by dephlegmation prior to secondary catalysis.

Other objects of the invention will be pointed out in the followingdescription and claims and illustrated in the accompanying drawingswhich disclose, by way of ex- 4 ample, the principle of the inventionand the best mode which has been contemplated of applying thatprinciple.

In the drawings:

FIGURES 1 and 1A constitute general flow sheet diagrams of a process towhich, for example, the method and apparatus of the invention areapplicable;

FIGURE 2 is a schematic vertical section of the materials charging zoneof gas-solid-solid contactor column;

FIGURE 3 is a schematic vertical section of the materials dischargingzone of the gas-solid-solid contactor column;

FIGURE 4 is a schematic vertical section of a typical columnar unit ofthe distillation zone of the gas-solid-solid contactor;

FIGURE 5 is a schematic horizontal section taken on 55 of FIGURE 2 ofthe contactor column;

FIGURE 6 is a schematic horizontal section taken on 66 of FIGURE 3 ofthe contactor column; and

FIGURE 7 is a schematic horizontal section taken on 7 7 of FIGURE 3 ofthe contactor materials discharge bins showing the over-fill safetyfeature.

The method and apparatus of this invention are applicable to thedestructive distillation of coal, lignite, oil shale and othercarbonaceous solids such as complex mixtures of municipal and industrialwastes. When used in conjunction with hydrogenating catalysts in ahydrogen atmosphere described herebelow, light, stable hydrocarbonsconstitute the entire distillate of the system.

The following description is given by way of example of the distillationof Rocky Mountain oil shale for the direct production of light, stablehydrocarbons, nearly all of which fall within the temperature range ofgasoline.

In the present example of extracting light, stable hydrocarbons fromRocky Mountain oil shale by direct, single step destructive distillationin the apparatus of the subject invention, it is necessary to considerthese thermal, chemical and physical factors:

(A) The heating and the pyrolysis of oil shale 1) The destructivedistillation of oil shale (when finely crushed) is completed in 60minutes when heated to 797 F. When heated to 842 F., the evolution ofvolatiles is substantially complete within 20 minutes. Reference: UnitedStates Bureau of Mine Report of Investigations 4744 of 1950.

(2) The net thermal input requirement to effect destructive distillationof oil shale is about 300 B.t.u. per pound, including drying. (In theprocess of the subject invention, about half of the total thermalrequirement is met by preheating and the balance is transferred from asolid heating medium within the reactor vessel as system pressure.)

(3) Shale must be preheated in a non-oxidizing atmosphere in order toprevent distillate loss by oxidation. Reference: United States Bureau ofMines Report of Investigations 6166 of 1963.

(4) Shale cannot be preheated without loss much above 400 F., becausethe evolution of volatiles begins slowly at about that temperature.Reference: Page- 14, Battelle Memorial Institute Report ofThermogravimetric Analysis, Aug. 12, 1965.

(5) When heated above 1000 F., oil shale calcine begins to absorb heatand evolve CO from carbonate destruction.

(B) Chemical considerations (1) In order to maximize the yield and tominimize the formation of the usual secondary coke polymer, ahydrogenating catalyst pellet must be mixed with the crushed shale. Forobvious economic reasons, the catalyst pellets must be of such size asto be physically separable and recoverable from the shale calcine. Tofurther stabilize the primary volatile matter, the hydrogen entrainedvapors must be promptly led through a sufficient bed of catalyst inorder to saturate olefinic double bonds and to remove oxygen, sulfur andnitrogen from organic combination.

In order to minimize carbonization and other deposits upon the secondarycatalyst surface, the hydrogen entrained vapors must be maintained inthe vapor phase and mist and dust must be first removed.

(2) Some three to eight moles of gaseous hydrogen per mole ofcondensable volatile matter must be introduced into the reaction zonesduring the destructive distillation of the oil shale. During primary andsecondary catalysis, from five to fifteen per cent of the hydrogenintroduced is consumed as chemical reactants in removing oxygen,nitrogen and sulphur from organic combination and in saturating olefins.

(C) Physical considerations (1) In the process of the subject invention,Rocky Mountain oil shale is nearly completely impoverished of thecementing organic matter and the calcine is, therefore, substantiallypulverulent, much of it being finer than 325- mesh or about 50 microns.The settling rate of 50 micron particles of shale calcine is somewhatless than one-half foot a second under system conditions. For thisreason, electric agminating by impingement upon larger teeteringparticles is an essential part of the process.

(2) When treating oil shale yielding ten weight percent of volatilematter, and introducing some three moles of hydrogen per mole ofvolatiles, the total standard volume is about 5,000 cubic feet per tonof oil shale. At system temperature and pressure of, say, 850 F., and300 p.s.i.a., the actual volume of gas entrained vapors becomes about750 cubic feet per ton of oil shale charged. This volume of gaseousmaterial must be continuously removed from the descending column ofincreasingly pul verulent gangue without serious entrainment of solids.

The general fiow diagram can be explained with reference to FIGURES land 1A wherein reactor 500 of this invention is shown schematicallybeing fed from three sources of different materials through lock 502 tobe described hereinafter. There is a source of solid supported catalyst504 which may be cobalt molybdate supported on alumina pellets, a solidheating medium 506 which is a different size from the catalyst pelletsin order to'allow separation by screening therefrom and may be anysuitable material which is resistant to thermal shock and capable ofbeing rapidly heated and cooled, and a feed of the hydrocarbonaceousmaterials 508 which may, in the described example, be crushed andpreheated oil shale. Each different material source includes dualcharging bins and locks shown in more detail in FIGURE 2 and may be skipfed byskip hoists 509. The materials are fed together into the reactor500 and passed through a plurality of zones as indicated and as will bedescribed in more detail hereinafter. Into each zone there is admittedmetered and preheated hydrogen which is heated at least to thetemperature of the system to furnish a hydrogen environment for thedestructive distillation accomplished by the solid heating medium. Asthe volatile matter of the hydrocarbonaceous materials is evolved duringthe destructive distillation, it is entrained in the hydrogen and ismetered out an offtake from each zone. Ahead of each offtake and withinthe column proper, there is provided an electric gas-fine solidseparator means 508 for each zone,,illustrated in more detail in FIGURE4. The volatile matter entrained in hydrogen may be passed to asecondary catalyst chamber 510, after first passing through a primarydephlegmator 511 to remove entrained SOlldS from the stream while alsoremoving high boiling point mist. The spent calcine from thehydrocarbonaceous material of oil shale, the catalyst pellets and solidheating medium pass through a lock 512 at the bottom of the reactorthrough a separator 514 which may be a screening type separator whichdiscards the calcine and separates the solid supported catalyst from theheating solid medium. The catalyst may then be recycled through recycleline 516, may be rejuvenated and cooled as desired by conventionalrejuvenation means 518 and recycled to feed chamber 504. For reasonsnoted earlier, the catalyst has greater heat capacity per unit ofsurface area than does the oil shale. Preferably the catalyst isintroduced into the reactor at a temperature 100 F. below that of theshale and picks up heat principally from the exothermic hydrogenatingreactions effected upon its surface. The heating solids are alsorecycled along line 520, may be reheated as desired by heating means 522and fed into the solid heating bin 506.

The polymers which boil above, say 450 C. entrained with whatever dustthat escapes the electrostatic dust separator means 508 are recycledfrom the primary dephlegmator 511 to the reactor 500. However part ofthis cooled liquid may be used for reflux in the primary dephlegmator.The 450 C. vapors and gaseous compounds relatively free of mist anddust, are passed to secondary dual catalyst chambers 510 and 510a usedalternatively. The catalytically hydrogen-stabilized product may then beled to a secondary dephlegmator 524 for condensation and removal of fourring and three ring aromatics plus saturates that boil between 300 C.and 450 C. The 300 C. vapors may then be further cooled in a teritaryreflux dephlegmator 526 from which naphthalene plus saturates which boilbetween 185 C. and 300 C. may be removed. A final condenser 528 mayfollow the teritiary dephlegmator 526 and from it alkylbenzenes withsaturates boiling below 185 C. may be removed. The uncondensed gasespass to a gas scrubber 530 for removal of H S, CO and NH and then toahydrocarbon gas absorbing scrubber 532 for removal of hydrocarbongases. Some hydrogen, with nitrogen, with nitrogen and carbon monoxide,are continuously bled off metered outlet 534 and the remaining gases,principally hydrogen, are raised in pressure by a compressor 536 andpumped into ahydrogen preheater 538. This preheater also receives anoutside supply of hydrogen 540. Preheated hydrogen is then admitted toreactor 500 at multiple levels and in metered amounts as shown in FIGURE1.

The internal operation of the reactor including the various locks, thegas-fine solid separating means and other features are described withreference to the remaining figures of the drawings.

Referring to FIGURES 2-7 for further description of the apparatus forpracticing this invention, there is shown in FIGURE 2 a dual catalystbin 2 and 3, a dual raw materials bin 5 and 7 and a dual bin 9 and 11for a solid heating medium. Catalysts bins 2 and 3 include undercuttingarc gates 13 and 15. Similarly, feed material bins 5 and 7 includeundercutting arc gates 17 and 19 and solid heating medium bins 9 and 11include undercutting arc gates 21 and 23. Additional gas-tight bottomvalves are provided below the undercutting arc valves in each of thelines from each of the bins as indicated at 25, 27, 29, 31, 33 and 35 ofFIGURE 2.

Suitable skip feeding or other feeding means for charging the bins maybe provided and the tops of each bin are provided with gas-tight topvalves as shown in FIG- URE 2 at 37, 39, 41, 43, 45 and 47. In addition,each bin includes a passage with valves for venting, these valves beingvalves 49, 51, 53, 55, 57 and 59 as well as valved lines leading intoeach bin for pressurizing the bin with purge gas, namely valves 61, 63,65, 67, 69 and 71.

Gas-tight chutes 73, and 77 are provided for the catalyst, for thehydrocarbonaceous feed materials and for the solid heating medium, andthese chutes discharge into feeder columns 79, 81 and 83, respectively.However, the chutes 73, 75 and 77 are gas-tight in respect to the gasdiffusion dome 103 and their respective source bins, but they arephysically separated from the tops of feeder columns 79, 81 and 83. Eachof these feeder columns has a gyratory feeder shelf 85, 87 and 89 orother suitable means to control the discharge out of the feeder tubeadjacent the bottom thereof.

A gas diffusion barrier zone 91 including gas sampling vent 109, isbelow the feeder columns and leads into an initial solid-solid contactzone feeder column 93 which has a gyratory shelf 95 or other suitablematerials flow controller at the bottom end thereof. Below feeder tube93 is the first gas-solid contact zone 97 and yet below is a secondsolid-solid contact zone of feeder tube 99 which has a second gyratoryshelf or flow controller 101 at the bottom thereof. Such typical unitsof the distillation zone are repeated as the throughput capacity of thesystem requires.

A gas diffusion dome 103 is at the top of the reactor and includes ametered purge gas inlet 105 and a metered purge gas outlet 107. Thesolid-solid contact column 93 includes a constricting throat 111 andabove the level of the constricting throat is a first vapor streamoff-take which may be metered. An annular hydrogen admission ring 115 isprovided in the reactant gas-solid contact zone 97 for admitting meteredhydrogen which may be preheated to the system temperature, but which mayor may not contribute to the net system heat input. Connected to theannular hydrogen ring 115 is a metered hydrogen inlet 117. The walls 119of reactor 500 may be suitably insulated and capable of carryingrequisite pressure.

There may be a plurality of similar distillation zones as shown inFIGURE 2 near the lower end thereof, and FIGURE 4 illustrates one ofthese zones in more detail. Referring to FIGURE 4, there is shown asolid-solid contact tube 401 and a gyratory feeder shelf 403 adjacentthe bottom thereof to control the feeding of solids out of solid-solidcontact zone defined by the interior of the tube 401. There is areaction zone defined by empty space 405 below the shelf 403 and anannular hydrogen admission ring 407 connected to the metered hydrogeninlet 409. One or more metered gas vapor olftakes 411 are provided atthe upper end of the gas-solid separating teeter column .300. Thedistillation unit illustrated in FIGURE 4 is identical with the othertypical distillation units comprising the distillation sections of thereactor 500 and they all may include the unique means for gas-solidseparation including a coalescing teeter column indication generally at300 and defined between the outside of the solid-solid contactor tube401 and the inside of the insulated pressure walls 119. -Because of theinwall batter of tube 401, the horizontal cross-sectional area of thegas solid separating chamber is smaller at the bottom than at the top,and thus forms a selective teeter column of suspended solid particleswhich are in equilibrium with the superficial velocity of the rising gasand, therefore, are in teeter. Within the teeter column the largerparticles collect the finer solid materials by electrical impingementwhich would otherwise be carried out of the apparatus by the flow of gasto the off-take 411. With oil shale calcine, the separation of thesefines from the gas stream is a particular problem. This inventionprovides several annular capacitor assemblies of low electricalresistance and fairly high capacitance consisting of vertical conductorsspaced from one to four inches apart by conducting rings on top andbottom of the assemblies. Each assembly of spaced conductors isconnected to an alternating current source and functions electrically asa capacitor. However, because of the collapsing and building electricfields afforded about the conductors, fine particles in suspension areeffectively coalesced and impinged upon the larger particles in teeter.The AC supplied by source 306 to the conductor plates, wires or tubes ofthe condenser assembly will cause the solids to coalesce upon teeteringgrains, thereby increasing their masses and, therefore, their terminalvelocities, causing the enlarged particles to settle from the gassolidseparating column. I

The lower limit of distillation zone 413 is shown in FIGURE 3 with amaterials discharge zone 417 therebeneath. This zone includes a gasdiffusion barrier tube 419 opening into a gas diffusion chamber 421through a solids material feeder 420. The chamber is provided with apurge gas metered inlet 423 and a metered vent 425. A lower gasdiffusion barrier tube 427 is provided at the lower end of chamber 421and the solids feeder means 426 are at the lower end of tube 427 leadinginto a discharge surge bin 431. There is a purge gas inlet 433 to thedischarge surge bin and a metered purge gas outlet 435 from the surgebin. The surge bin has dual outlets each provided with undercutting gate437 followed with a gas-tight discharge valve 439 in the left gate andundercutting gate 441 in discharge valve 443 in the right gate. Belowthese gates are calcine discharge pockets 449 and 451 of theirrespective bins which empty out through are cutting discharge gates 445and 447 followed by gas-tight discharge valves 453 and 455. Overfillesafety pockets are controlled by providing at their top drop gate valves457 and 459. Each chamber includes a purge gas by-pass line with valves461 and 463. Purge gas vents are controlled by valves 465 and 467 whilepurge gas inlets are controlled by 473 and 475. Purge gas by-pass ducts469 and 471 lead from the pockets 449 and 451 to the materialsdischarging zone 431.

FIGURE 2 schematically shows a vertical section of the three pairs ofmaterials charging bins and the upper part of the gas-solid-solidcontactor and is used for reference in the following description andexample of the process when treating Rocky Mountain oil shale.

With all gates 13, 15, 17, 19, 21, 23 and lower valves 25, 27, 29, 31,33 and 35 closed, fill one of the dual left hand bins 2 with, say,Ai-inch catalyst pellets at about 800 F. Fill one of the center dualbins 5 with oil shale which is preferably preheated above 400 F. andcrushed so that one dimension of the largest fragment is less than, say,-inch. Also fill one of the right hand dual bins 9 with a heatingmedium, such as inch alumina spheres which have been heated to, say,1600 F.

Close the upper gas-tight valves 37, 41, 45 and close vent valves 49,53, 57. Admit preheated purge gas by opening valves 61, 65, 69 topressurize each of the filled bins to system pressure with purge gasfrom high pressure purge gas main (not shown), say, to 300 p.s.i., whichwould be equal to the pressure within the gassolid-solid contactorcolumn 2, and proceed to fill the second of each of the dual bins 3, 7,11, to be likewise subsequently pressurized.

Open valves 25, 29, 33 and then open undercutting arc gates 13, 17, 21,to permit the three types of solids to fill ducts 73, 75, 77, and feedercolumns 79, 81, 83.

Superheating of the preheated shale to the temperature of destructivedistillation is begun by causing the gyratory feeder shelves (my priorissued Patent No. 3,083,471) to gyrate at such speed and amplitude thatthe three solids are fed in the desired proportion into the solid-solidcontact column 93.

It should be noted that the materials chutes 73, 75, 77, terminate ashort distance above the top of their respective feeder columns 79, 81,83. Therefore, direct gas flow by differential pressure from thematerials chutes to the diffusion barrier zone 91 is interrupted and anygas which is forced to move either up or down must approach the averageanalysis of the gas within the diffusion dome 103.

Even though the gas diffusion potential of the reacting gas may beproportionately high, which in this example is hydrogen, its partialpressure can be maintained at a desirably low figure, either by holdingthe purge gas pressure in the charging bins somewhat above the contactorcolumn 1 pressure, or by admitting purge gas through inlet and, in bothcases, metering the diffusion gas out through purge gas outlet 107.

Because the diffusion potential of hydrogen is much greater than that ofthe purge gas, the two gases cannot be kept from mixing to some degree.Therefore, the separate chamber or diffusion barrier 91 is providedbetween the purge gas section above the hydrogen section below so thatneither pure hydrogen can diffuse upwardly 9. I nor pure purge gas beforced downwardly. The analysis of the gases within the diffusionbarrier zone is checked at metered vent 109 and the hydrogen content iskept well below equilibrium by adjusting the over pressure in diffusionzone 103.

As a further resistance to hydrogen diffusion upward into the diffusionbarrier, the solid-solid contact column is maintained full of mixedsolid material, well above its constricting'throat 111, by its feedershelf reacting to a density sensing device (not shown). Furthermore,hydrogen diifusion upward is further impeded by the downward movement ofthe mixed solids within the solid-solid contactcolumn 93, which is quiterapid.

The purpose of the gas diffusion barrier zone 91 and the gas diffusiondome 103, the pressurization and continuous purging of the materialscharging section is to effectively eliminate any reasonable likelihoodthat an explosive mixture of air and hydrogen could form.

As a further means of limiting the diffusion of hydrogen upward throughthe solid-solid contact column 93, theanalysis of gas leaving with theinitial vapor stream metered off-take 113 is keptto, say, fivevolumepercent of purge gas by maintaining a suflicient over pressure inthe gas diffusion dome 103 and in the charging section above.

Mixed solids in the desired proportion, having been fed proportionatelyfrom feeder tubes 79, 81, 83, leave the first solid-solid contact column93 over the periphery of gyratory materials control shelf 95. As thesolid cascade falls through the empty gas-solid contact zone 97 andradially outboard of annular hydrogen admission ring 115-, it must slideacross and over the continuously admitted annular stream of hydrogen,entering by metered inlet 117, insuring fairly uniform, thoughmomentary, gas-solid contact.

The volume of preheated hydrogen admitted through inlet 117 and takenoff through metered ofitake 113 is primarily limited by the allowablevertical superficial gas velocity in the annular space between thesolid-solid contact tube 93 and the major contactor pressure walls 119.Furthermore, the time of contact (through hydrogen) between the hotsolid medium and the raw material has, so far, been short and only asmall portion of the latter can have been heated to distillationtemperature. Therefore, only a fraction of the total hydrogenrequirement need be met in this initial stage or in any one subsequentstage of progressive distillation.

. Following the initial gas-solid contact between the progressivelyheating raw material in empty space 97, the various solids again gatherinto intimate contact as they enter solid-solid contact tube 97, to becontrollably discharged once more into the succeeding gas-solid contactspace below.

For a more detailed description, please refer to FIG- URE 4, which is atypical unit of the repetitive stepwise heating, distillation andprimary contact catalysis section of the total composite gas-solid-solidcontactor column. As has been briefly explained above, the distillationsection of the 'gas-solid-solid contactor columnar assembly is comprisedof a series of these identical units which accomplish in a stepwisefashion, the heating of the raw material to distillation temperature bysolid-solid contact with a solid heating medium, both of which are in anatmosphere which is chiefly hydrogen during each downward passagethrough typical tube 401. Of course, the relatively high thermalconductivity of gaseous hydrogen greatly speeds and assists the solid tosolid heat transfer function.

The residence time requirement for heating the shale to distillationtemperature and for complete evolution of volatile matter is met byproviding a sufficient number of sequential, typical solid-solid contacttubes 401.

As the mixture of the solid materials, which in this example consists ofalumina-supported catalyst pellets, crushed oil shale and hot aluminaspheres, is metered from typical solid-solid contactor tube 401 over therim of typical gyratory metering shelf 403, the mixture of solids dropsthrough hydrogen in typical empty space 405 to land radially outboard ofthe typical annular hydrogen admission ring 407. Hydrogen admittedthrough typical annular ring 407 from typical metered inlet 409 flowsupward through the solid mixture, momentarily entraining the finerfragments and insuring intimate gas-solid contact.

The throughput capacity of the system is limited by three time-dependentfactors; the first is the rate at which hydrogen-entrained vapors can bewithdrawn through metered gas outlet 411 to secondary catalysis,relatively free of entrained solids. The second is the rate at whichheat can be transferred from the heating medium to the crushed oil shaleand the third time-dependent factoris the rate of volatile matterevolution after the shale has reached its distillation temperature.

The mechanics of separating fine solids from the hydrogen-entrainedvapor is obviously of paramount importance to the successful andcontinuous operation of the system. The. approximate settling rate ofSO-micron oil shale particles in hydrogen at system temperature, andpressure, say 800 F. and 300 p.s.i.a., is about one-half foot persecond. A substantial part of oil shale calcine produced by this processinvention is finer than fifty microns. Furthermore, about one-half foota second is the minimum practical superficial gas velocity within thedistillation column of the subject invention if a commercial rate ofdistillation is to be obtained. Therefore, it becomes necessary to causethe finely entrained shale particles to agminate and so to increasetheir settling rates beyond the superficial gas velocity.

In the subject invention, referring again to FIGURE 4 and particularlyto the gas-solid separation zone, metal wires, narrow plates or tubesare hung from concentric rings electrically insulated from thecontaining vessel, spaced, say, from one to four inches both radiallyand circumferentially, depending upon the size and type of service andthe degree of gas cleanliness desired. The assembly has appreciablecapacitance and low resistance and its electrical characteristics aresimilar to those of a conventional condenser. When connected to analternating current source, the collapsing and building of the electricfield, and its rapidly changing sign, causes suspended particulatematter to agminate into larger particles of higher settling rates thanthe initial dispersoids. (Please refer to my issued Patent No. 3,100,146which discloses the electrical coalescing of ultra minute particles intolarger, filterable sized particles.) In the process of this subjectinvention, the fine particulate matter is not collected upon any fixedelectrode, but rather is caused to impinge upon larger particles inequilibrium in the rising gas stream, which are in teeter.

Thus, the teetering particles are continuously caused to grow in sizeand progressively move downward to a lesser horizontal area and to aregion of higher gas velocity, until they finally grow sufficientlylarge to fall below the level of the gyratory feeder shelf 403.

The principle of electrically causing very finely divided gas-entrainedparticulate dispersoids to coalesce without precipitation upon acollecting, fixed electrode is disclosed in my Patent No. 3,100,146.This invention differs from my earlier disclosure in that the teetergrains of dust, which are in equilibrium with a rising gas stream whichdecreases in superficial velocity from bottom to top of the containingvessel, are employed as the autogenous nuclei for particulateagmination.

When the oil shale has been impoverished of volatile matter and the gasstream exhausting through the lowest typical metered gas-vapor outlet411 has a negligible vapor content, distillation is complete and thecalcine, together with the catalyst pellets and the solid heatingmedium, must be discharged from the system. In order to insure againstan explosive condition when discharging hot hydrogen-impregnated solidsinto the atmosphere, a non-combustible purge gas must be exchanged forhydrogen before atmospheric contact. The exchange of purge gas forhydrogen and the discharge of solids from the pressurized distillationcolumn are accomplished in the following manner:

FIGURE 3 illustrates the lowest distillation unit 415 and the entire gasexchange and solid materials discharge zone 417.

When the solid materials enter gas diffusion barrier 419, the oil shalehas been destructively distilled, ending the evolution of combustiblevolatiles. The interstices and voids within the mixed solids containhydrogen which is removed by diffusion into the large volume of purgegas occupying the gas diffusion chamber 421. The concentration ofhydrogen is maintained at a low level as purge gas is metered intochamber 421 through purge gas inlet 423 and the mixture of hydrogen andpurge gas is metered out through vent 425.

The solid material entering the second gas diffusion barrier tube 427 issubstantially free of hydrogen, and any remaining hydrogen is dilfusedaway into the purge gas occupying surge bin 431 as the solid materialfalls over the periphery of gyratory feeder shelf 429. The hydrogencontent of the gas mixture in surge bin 431 is also kept below anacceptable level by metering purge gas through inlet 433 and exhaustingthe gas mixture through metered purge gas outlet 435.

The discharge of solids from the gas-solid-solid contactor column isdescribed in the following operating sequence. Referring again to FIGURE3, undercutting gate 437 and gas-tight valve 439 are open, whileundercutting gate 441 and gas-tight valve 443 remain closed. Also, atthe beginning of the calcine discharge operation, undercutting arc gates445 and 447 and gas-tight valves 453 and 455 remain closed. Drop gates457 and 459 also remain closed at the beginning of the calcine dischargeoperation.

As calcine is discharged from surge bin 431 through valves 437, 439 or441, 443 into the respective bins 449, 451, valves 457 and 459 remainclosed, leaving the overfill safety chambers empty. The other chambers449, 451 are completely full, however, which would normally prevent theclosing of valves 439 and 443. Undercutting arc valves 437 and 441,being so designed, are then closed across the column of broken solids.Subsequently, swing type chute gates 457 and 459 are dropped open tofill up the overfill safety and drain out the solid materials whichwould otherwise block the gas-tight closing of valves 443 and 439. Thesevalves may then be closed to form gastight seals and the bottom valvesfor chambers 449 and 451 may be safely opened to the atmosphere afterdepressuring through vents 467 and 465.

The three classes of solids, pulverulent oil shale calcine, catalystpellets and the solid heating medium, by virtue of their sizedifferences, are separated by separator 514 (FIGURE 1) which may be aconventional double deck screen (not shown). The calcine is sent towaste, while the catalyst pellets and heating medium are separatelyrecycled, following their respective suitable rejuvenation and reheatingor cooling.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention.

What is claimed is:

1. A method for the destructive distillation of hydrocarbonaceous solidsincluding stabilization en masse of the primary volatile matter,comprising:

(a) mixing a physically separably solid supported stabilizing catalystwith a mass of particles of the hydrocarbonaceous material,

(b) heating the mixture to a temperature sufiiciently high to causedestruction distillation of the primary volatile matter in thehydrocarbon to begin and proceed, said distillation being effectedwithout the benefit of said catalyst,

(c) stabilizing the primary volatile matter in the presence of thecatalyst and an environment of essentially hydrogen,

(d) removing the stabilized volatile matter by hydrogen entrainment,

(e) physically separating all solids from the entrained volatile matter,and

(f) separating the devolatilized hydrocarbonaceous solid from the solidsupported stabilizing catalyst.

2. A process as claimed in claim 1 wherein heating is accomplished bymixing another physically preheated inert solid with the catalyst andhydrocarbonaceous material.

3. A process as claimed in claim 2 comprising separating the heatedinert solid from the solid catalyst and the devolatilized material.

4. A process as claimed in claim 1 comprising further catalyzing theremoved volatile matter, after partial dephlegmation with a stabilizingcatalyst.

5. A process as claimed in claim 1 further comprising recycling thecatalyst and rejuvenating and cooling during the recycle when necessary,and providing a catalyst with a greater heat capacity per unit ofsurface area than the hydrocarbonaceous solids.

6. A process as claimed in claim 1 further comprising preheating thesolid hydrocarbonaceous material to just below the temperature ofdistillation, the preheating being accomplished just before sizing.

7. A process as claimed in claim 1 wherein the hydrocarbonaceousmaterial is oil shale, coal or tar sand.

8. A process as claimed in claim 1 wherein distillation and removal ofgas-entrained volatiles are accomplished at a plurality of separatezones.

9. A process as defined in claim 1 wherein the separation of solids isaccomplished during the removal by electrical agglomeration of thesolids in a teeter column zone.

10. A process as defined in claim 1 further comprising partiallycondensing the higher boiling point compounds of the removed volatilematter entrained in hydrogen and scrubbing out any entrained solids, andthen performing a final stabilizing catalysis on the removedhydrogen-entrained vapor stream.

11. A method for the destructive distillation of hydrocarbonaceoussolids comprising:

(a) controllably feeding hydrocarbonaceous solids through a plurality ofsequential vertical distillation zones,

(b) controllably heating the hydrocarbonaceous solids in the presence ofa physically separable catalyst in the distillation zones to distillvolatile matter therefrom,

(c) providing a gaseous environment in the distillation zones consistingchiefly of hydrogen,

(d) controllably withdrawing the evolved volatile matter entrained inthe hydrogen from each distillation zone,

(e) preventing within each distillation zone the withdrawal of solidswith the hydrogen entrained volatile matter by electricallyagglomerating any solids carried by the hydrogen entrained volatilematter while flowing upward through a region of widening area in eachdistillation zone, and

(f) removing solids from the lowest of the distillation zones.

12. A method as defined in claim 11 further compris- (a) providing thehydrogen environment in the distillation zone under at least 10atmospheres pressure,

(b) feeding and withdrawing the solids through nonexplosive lockingzones, and

(c) preheating the hydrocarbonaceous solids prior to their being fed tothe distillation zone.

13. A method as defined in claim 11 wherein the electric agglomerationof fine particles upon autogenously supplied nuclei utilizes a highpotential alternating current field.

14. A method as defined in claim 11 further comprising condensing highboiling liquid mist and simultaneously scrubbing out any entrainedsolids from the withdrawn stream of distillate volatile matter andhydrogen, and then finally catalytically stabilizing the uncondensedvapor stream.

15. Apparatus usable for the destructive distillation ofhydrocarbonaceous materials comprising:

(a) a vertical reactor capable of withstanding temperatures of up to1000 F. and pressures to 30 atmospheres,

(b) means to controllably feed three separate and separable solidmaterials (such as a solid supported, separable catalyst,hydrocarbonaceous raw material, and a solid heating medium) throughpressure locks to the reactor,

(c) means within the reactor to define a plurality of adjacentvertically positioned distillation zones each separated by acontrollable solid material feed means providing a gaseous difiusionbarrier between zones,

(d) gaseous intake and ofitake means for each distillation zone withinthe reactor,

(e) a combination A.C. agglomerator and widening gaseous path in eachdistillation zone in front of the olftake means for separating gasesfrom fine solids, and

(f) means for removing the solid materials through a pressure lock fromthe bottom of the reactor.

16. Apparatus as defined in claim 15 wherein the controllable solid feedmeans separating distillation zones includes a frustoconical feed tubewith its greatest diameter at its bottom and a shelf feeder at thebottom of the feed tube.

17. Apparatus as defined in claim 15 wherein the combination A.C.agglomerator and widening gaseous path include a plurality of spacedannular plates of appreciable surface and low resistance positionedwithin the reactor and outside the frustoconical feed tube so that theshape of the feed tube provides the widening gaseous path.

References Cited UNITED STATES PATENTS 2,726,998 12/ 1955 Findlay 201-203,100,146 8/1963 Huntington --9 3,224,954 12/ 1965 Schlinger et a1 208113,244,615 4/ 1966 Huntington 208-11 3,247,092 4/1966 Huntington 20883,231,486 1/1966 Perry et a1 20810 NORMAN YUDKOFF, Primary Examiner D.EDWARDS, Assistant Examiner U.S. Cl. X.R.

